The pass emits a call to sqrt that has attribute "read-none". This call will be
converted to an ISD::FSQRT node during DAG construction, which will turn into
a mips native sqrt instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183802 91177308-0d34-0410-b5e6-96231b3b80d8
